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(No Model.) 3 ShetsSheet 1.

A. ROLLASON.

GAS-0B. GALORIG ENGINE.

No. 391,338. Patented 001:. 16, 1888.

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3 Sheets-Sheet 2.

(No Model.)

A. ROLLASON.

GAS 0R OALORIG ENGINE.

Patented Oct. 16. 1888.

N. PETERS. F'hoXGLilhOgr-Ipher. Walhinglan. D. Q

3 Sheets-Sheet 8.

(No Model.)

A. ROLLASON.

GAS 0R OALORIO ENGINE.

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UNITED STATES ARTHUR ROLLASON, OF LONDON, COUNTY OF MIDDLESEX, ENGLAND.

GAS OR CALORIC ENGINE.

SPECIFICATION forming part of Letters Patent No. 391,338, dated October 16, 1888.

Application filed December 8, 1886. Serial No. 220,997. (No model.) Patented in England June 2. 1886, No. 7,427, and Septemlml' 29, 1:86, No. 12,368; in France July 23, 1886, No. 177,568; in Germany July 25, 1886, No. 39,568; in Belgium December 14, 1886. No. 75,597; in India May 2, 1887, No. 84, and November 11, 1887. No. 213; in Victoria. May 12, 1887, No. 5,067; in South Australia May 27,1887. No. 813; in Queensland May 31, 1887, No. 285; in Canada June 23, 1887, No. 27,026, and in New South \Vales July 30, 1887, No. 2,120.

To all whom, it may concern.-

Be it known that I, ARTHUR RoLLAsoN, a subject of the Queen of Great Britain and Ireland, and a resident of 53 Queen Victoria Street, London, in the county of Middlesex, England, havein vented'certain Improvements in Gas or Caloric Engines, (for which I have obtained British Patent No. 7,427, dated June 2, 1886, and British Patent No. 12,368, September 29, 1886; French Patent No. 177,568, July 23, 1886, and German Patent No. 39,568, July 25, 1886; Belgian Patent No. 75,597, December 14, 1886; Victorian Patent No. 5,067, May 13, 1887; South Australian Patent No. 813, May 27, 1887; New South Wales Patent No. 2,120, July 30, 1887; Queensland Patent No. 285, May 31, 1887; Indian Patent No. 81, of 1887; Indian Patent No. 213, of 1887, and Canadian Patent No. 27,026, June 23, 1887,) of which the following is a specification.

The nature of my invention consists in the construction and arrangement of a gas or caloric engine in which a combustible mixture of gas or vapor and air is compressed in a chamher in connection with the cylinder prior to its ignition in such chamber, so as to increase the explosive energy of such mixture and to utilize as far as possible the energy developed by the ignition ot'such mixture, and at the same time to obtain the most economical results of working.

In the arrangement which is the subject of my invention 1 endeavor to obviate the disadvantages of existing gas-engines and to carry out the following principles, the importance of which has been demonstrated by experience:

First. To obtain the most economical results in gas or caloric engines, it is necessary that the temperature of the heated gas or vapor should be as low as possible in relation to a high initial pressure, and that such heated gases or vapors should be in contact with the walls of the cylinder for as short a time as possible, so as to minimize the loss of heat'by conduction through the walls, and hence it follows that the greater the piston speed of the engine the less will be the loss through the cylinder-walls in proportion to the power developed.

Second. In order to obtain rapid working, it is necessary to provide against premature explosions of the compressed charge.

Third. In order to obtain the advantages of rapid working without loss in other directions, it is necessary that the combustion of the charge should be complete as near the commencement of the stroke as possible in order that the full advantages of expansive working may be obtained.

Fourth. In order to work economically with an explosive charge, it is necessary to provide against the excessive loss of heat which would arise from the very high initial temperature of the exploded charge in engines of the ordinary construction.

Fifth. To obtain further economy, the regenerative principle of working should be adopted as far as practicable in order to economize some of the waste heat of the engine.

Sixth. In applying the regenerative increment of heat to the incoming charge it is important to add this increment as far as possible after compression.

I employ a cylinder which has a chamber for compression and ignition of the combustible charge in connection therewith, forming a prolongation of the cylinder beyond the extreme point to which the stroke of the piston reaches. I provide means whereby the temperature of this chamber may be maintained at as high a point as practicable, While the wearingsurface of the cylinder is kept cool in the usual manner. To guard against premature and accidental explosions and to keep the temperature of the chamber within proper limits, and to get rid as far as possible of the products of combustion still remaining in the combustion-chamber after the completion of the next back-stroke of the piston after explosion, I introduce a cooling-charge into the cylinder and expel it prior to the introduction of the explosive charge. I surround the walls of the compression or ignition chamber with an air-space lining or lagging, so that the heat 1 communicated to such walls may be retained as far as possible in such walls instead of being conducted away. I employ an explosive charge the combustion of which is practically complete at the moment of ignition. This caloric insulation of the compression and ignition chamber serves a twofold purpose. By preventing the escape of heat as far as possi: ble from the Walls of the ignition-chamber I obviate the great loss of heat at the moment of ignition. Moreover, by retaining heat in the walls of this chamber I heat the incoming charge regeneratively in the manner herein after described. Further, according to my invention the explosive charge is admitted into the cylinder in such order of composition that on the completion of the compression-stroke of the piston, and at'the moment of the addition of the aforesaid regenerative increment of heat and of ignition, the weaker or weakest part of the compound is located next to the firing-port and the richer part next the piston. This stratification is also aided and made uniform by the'provision of means for regulating the gas or vapor consumption in exact proportion to the work being done by the engine.

In the accompanying drawings, Figure l is a plan of engine with exhaust-valve, governor, and part of the gas regulating slide-lever removed. Fig. 2 is an elevation partly in section. inder with slide-cover removed and showing slide and working parts connected therewith in position for ignition, showing also governor and gas-regulating slide. Fig. 4is an elevation of slide-cover,showing gasvalve partly in section. Fig. 5 is a horizontal section on line a b, Fig. 3, with slide-cover attached. Fig. 5 is a sectional view of a modification. Fig. .6 is a vertical section on line a d, Fig. 3, showing slide moved into position to take in the charge. Fig. 7 is a cross-section on line cf, Fig. 3, showing gas valve and regulatingslide. Fig. 8 shows one method of operating the gas-valve. Figs. 9 and 10 are vertical sections through exhaust-valve, showing means of operating same and connection to exhaustpipe. Fig. 11 is a part vertical section through combustion-chamber, showing air and water spaces; and Figs. 12 and 13 are diagrams, hereinafter referred to. v

In all of these figures the parts are shown in a position just previous to ignition, and similar letters of reference designate corresponding parts.

A is the working-cylinder, of ordinary construction, mounted on a bed-plate and surrounded with a water-jacket, a, provided with circulating-pipes a a in the usual manner, whereby the wearing-surfaces of the workingcylinder are kept as cool as possible. The cyl-, inder A is fitted with a piston, B, provided with any suitable ring-packing and connected.

by a rod, 72, to crank O of crank-shaft 0, upon which is keyed a fly-wheel, a, and drivingpulley c in the usual manner.

A is the space or chamber in connection Fig. 3 is a back end elevation of 03 1- with the working cylinder A, wherein combustion of the charge takes place. It is also surrounded by the water-jacket a,- but between the water-jacket a and the chamber A a second space, a", is provided, open to the atmosphere, which space may be,if desired,filled with slag-wool or other suitable non-conductor of heat, whereby the temperature of the chamber A is maintained at as high a point as practicable and loss of heat reduced to a minimum. Instead of an airspace, the chamber may be lined with porcelain or enamel or other suitable non conductor of heat, or may be lagged externally. The air-space may extend round the back of the combustion-chamber; but the wearing-surfaces of the slides should be kept cool by water-circulation, as usual.

11 is a worm or bevel wheel fast on the crankshaft, gearing with a second wheel, d, on a counter-shaft, D, revolving in suitable bear ings in the proportion of three to one, so that the shaft D revolves once for every three revolutions of the crank-shaft. On the other end of the counter-shaft D a crank, E, is fixed and connected by rod 6 to the lever e, centered at e connected to the slide F, working between the face F and the cover F The crank E is preferably a disk-crank and carries on its periphery a cam, 6 which at each revolution engages with a roller upon a bent lever, e suitably centered at e and actuating the spindle g of the gas-admission valve G in the slidecover F which is provided with a spring, The passage 9 from the valve, as shown dotted in Figs. 4 and 5, terminates on the inner face of the cover in a suitable number of apertures, g 9 Upon the countershaft D is also-fixed a bevel-wheel, H, gearing with a pinion, h, Working a governor, h, of any suitable centrif ugal type. The governor h is provided with a collar, 71. on which rides the forked end of a bell-crank lever, h, centered at h and actuating a grid-slide, 6, working in any suitable position on the outer or admission side of the gas-valve G, regulating the supply of gas through pipe I, upon which is provided the usual stop-cock; or, by another arrangement, Fig. 5, a slide, '5 provided with one aperture, i, may be fitted and connected with the governor to work across the gas-admission port g on the inner face of the slide-cover F, as hereinafter more particularly set forth.

J is the air-admission port. K is the masterlight, and 7c the gas-supply to same. k is the gassupply to the traveling light by means of groove k on inner surface of the slide-cover F".

Fig. 6 shows the passage L and ports Z with air-passage o,forming the connection between the master and traveling lights, whereby the gas-supply to the traveling light is ignited and the flame subsequently, as shown dotted, projected by the pressure of the compression into the ignition-orifice, as hereinafter described.

M is the admission and firing port, which has parallel sides, as seen in Fig. 1.

N is the exhaust-port, in which is fitted the valve 02, actuated at the proper times by a double cam, a, as hereinafter described. A port, M, is formed in the slide F, as shownin Figs. 5 and 5, having three ways-the first, g, controlling the gas-supply g,- the second, j, controlling the air-supply J ,and the third, m, controlling the admission-port M.

In asingle-acting engine constructed according to my invention the arrangement which presents the greatest advantages is one in which the cycle of the engine is complete in three revolutions of the crank-shaft. Starting from the phase of the cycle in which the piston has completed a stroke and has behind it a compressed charge ready for ignition, the operations of the engine take place in the following order: first, explosion of the charge and consequent outstroke of the piston; second, instroke of piston, expelling part of products of combustion through exhaust N; third, outstroke of the piston, takingin a cooling-charge of atmospheric air through air-port J; fourth, instroke of piston, expelling cooling charge, together with the remaining products of combnstion,through exhaust N; fifth, outstroke of the piston,taking in explosive mixture through gas-port G and air-port J; sixth, instroke, of the piston, compressing explosive mixture.

If the insulated compression and ignition chamber A, hereinbefore referred to, were used with a two-revolution cycle engine without the introduction of a cooling-charge, it would be found that the heating of the charge due to the combined effect of compression and the regenerative action of the lining of the compression chamber would often fire the charge before the proper time. The introduction of a cooling-charge is therefore necessary in order to prevent this result; but I wish it to be understood that I am aware that the use of the cycle of operations above described in a gas-engine is not new.

Commencing with the first of the six divisions of the cycle of operations, the ignition of the compressed charge causes it to explode at once, all ports being closed, thereby producing a very high degree of pressure in relation to the comparatively low temperature effected by the aforesaid cooling-charge. The heated gases, however, being in contact during the commencement of the stroke chiefly with the walls of the insulated ignition-chamber A,the loss of heat from the initial temperature is small. The piston moves forward under the influence of the pressure, and by the time that the ignited gases come into contact with the cooler parts of the cylinder a considerable amount of ex'pansion,with consequent further reduction of temperature, has taken place. The piston completes its stroke under the influence of the pressure of the ignited charge, expansion being carried out as far as possible. Upon the return stroke of the piston the cam n raises the exhaust-valven and the products of combustion are expelled through port N. Upon the next outstroke of the piston the slide moves so as to open the air-port J, all other ports remaining closed,and the charge of cool air is drawn into the cylinder, and, directed by the parallelsided admission-port M, passes through the center of the products of cornbustion left in A in a stream until it meets the back of the piston, when it branches off, as shown diagrammatically by dotted lines in Fig. 12, the portion which has first entered returning to the combustion-chamber, leaving the portion that has entered last next the piston, and the greater part thereof, together with the remaining products of combustion, is expelled by the next instroke of the piston through exhaust-port N,whose valve n is actuated by cam a, as before described. The condition of the cylinder is now as follows: The portion of the cylinder swept out by the piston is comparatively cool, but the lining of the compression-chamberis still highly heated and is in contact with the remaining portion of the cooler air which has been drawn in, as before mentioned. Upon the next outstroke of the piston the slide F is moved until the ways in, g, andj of slide-port M coincide With the admission gas and air inlets M, g", and J, and the explosive charge flows in, following the outward movement of the piston. -At the same time the traveling-light port L,with its passages Z, assumes the position shown in Fig. 6, and the gassupply k to the traveling light passing along the groove on the inner face of the cover F is reignited, ready to fire the mixture, as hereinafter shown. The incoming charge does not, however, immediately come into contact with the heated lining of the compression-chamber, but, directed by the parallel-sided admission-port M,passes in a stream, as indicated diagrammatically in Fig. 12, and comes first into contact with the working-sun face of the cylinder, which, being kept comparatively cool by the water-jacket a, heats the incoming charge but slightly. From its acquired velocity the incoming charge becomes greatly diffused and the particles of combustible gas or vapor become mechanically mixed and brought into more intimate and effective contact with the particles of the air, thus rendering the whole mixture of a much more explosive nature. The first portion of the combustible gases taken in mixing, as described, with the air in front, becomes diluted and returns to the back of the chamber A, and surrounds the firing-port M, While the portion taken in last flows to and remains behind the back of the piston. In this order-that is tosay, the Weaker part of the mixture being next the firing-port, while the richer part is next the piston, as shown diagrammatically in Fig. 13- the whole charge is compressed in the chamber A; but the heating effect of the lining of the compression-chamber A. upon the explosive charge does not take effect greatly until the instroke of the piston is nearly completed. The slide is now moved from the. position shown in the figures, making the connection shown dotted in Fig. 6,when the baek-pressure of the compressed charge forces the flame IIO down passage Z, through port L, and proj ects it into the combustion-chamber A,when the weaker part of the charge is ignited and burns with great rapidity and the piston travels forward with great velocity, thus avoiding the shock which would otherwise be caused by firing into the richest part of the mixture. By this arrangement it will be seen that the increment of heat which is added to the corn pressed charge is chiefly given not at the commencement of the instroke of the piston and before compression, as in some engines, but when the compression is nearly completed, whence results a considerable economy in working.

With the above arrangement I am enabled to work the engine more rapidly than can be done with existing forms of gas-engines, with certainty of ignition, without risk of premature or accidental explosions, with the full advantage of complete expansion of the ignited charge, and with the saving effect due to the regenerative action which is involved in the arrangement,and to the economy ofheat which takes place at or about the time of ignition. Moreover, the arrangement is such that although an explosive charge is used,there is an absence of shock or noise.

The action of the governor is as follows. \Vhen the work being done by the engine is reduced,the excess speed,raising the governor and collar h and forked end of arm h of bellcrank lever, withdraws the grid-slide '5. The apertures formed in the grid-slide 2' normally coincide with the aperture of the gas-supply pipe I, and on the slide being withdrawn, as described, the solid end part of the grid comes partly over the supply-pipe I, thus varying and regulating the gas consumption at any period of the stroke in exact proportion to the work being done by the engine. In other words, the area of the gas-admission port is varied in exact proportion to the speed of the piston, and in consequence the tension in the cylinder is maintained constant throughout the outstroke.

In the arrangement shown in Fig. 5 the slide '5 with its aperture i, (normally coinciding with the gas-port 9 is controlled and actuated by the governor in an inward direction. The gas-port g and slide-port g, as shown in Fig. 5, are in this case reversed, 9 being rectangular and g a series of apertures similar to those shown at 9 Fig. 4. As before described in the case of the grid-slide i, the excess speed of the engine due to the reduction of work is utilized to raise the collar of the governor and by suitable compound lever pushes theslide inward, reducing the area of the gasport g and increasing the distance between it and the port 9. The period at and during which the charge of gas is drawn in through admission-port M and port M is delayed and diminished, and the richness of the explosive charge thereby reduced.

As I have already said, it is not new to construct a gas-engine having the cycle of operations described above-that is, explosion of the charge, expelling part of the products of combustion, drawing in a scavengering-charge of air, then expelling most of this charge,then taking in the explosive mixture, and finally compressing the latter. In such engines the cycle of operations is complete in three revolutions of the crank-shaft, and such an engine is termed a three-cycle engine. So far as I am aware, however, no three-cycle engine has heretofore had a parallel sided admissionport for the scavengeringcharge of air and,

for the explosive mixture located centrallyin the end of the cylinder and combined with means for regulating the admission of gas in proportion to the piston speed,so as to insure, in the first place, the complete driving out of all burned gases, and, in the second place, the stratification of the explosive mixture in the cylinder, above described, with the weakest mixture next the firing-port and the richest next the piston, and, so far as I am aware, no such three-cycle engine has had a regenerative jacket combined with means for obtaining this stratification. Gas-engines have been made with regenerative jackets before, but have been objectionable because they caused premature explosions on back ignitions, as they are termed, owing to the facts that more or less burned gases have been left in the cylinder, and also that the richest gases were next to the firing-port.

By constructing the three-cycle engine with a central admission-port in the end of the cylinder, so that, on one hand, all the products of combustion are driven out, and, on the other hand, the weakest part of the explosive charge is placed next to the firing-port, while the richest part is next to the piston, the regenerative chamber can be used without danger of premature explosions.

I claim as my invention 1. A three-cycle engine having a parallelsided admission-port for the air and gas at the center of the end of the cylinder, combined with means for regulating the gas-admission in proportion to the piston speed, as and for the purpose set forth.

-2. A three-cycle engine having an admission-port for the air and gas at the end of the cylinder, and having a regenerative jacket around the combustion-chamber, as and for the purpose set forth.

3. The mode herein described of supplying air and gas to gas-engines so as to produce instantaneous explosion and complete combustion almost at the moment of ignition, said mode consisting in first expelling all the products of combustion after the explosion except what remains in the combustion-chamber, then drawing in centrally at the same end of the cylinder a scavengering-charge of air through and past the said products of combustion, then expellingaportion of the charge of air, such portion containing all or nearly all the said products of combustion remaining in the combustion-chamber and leaving IIO therein a body of pure or nearly pure air, then drawing in an explosive charge through said body of air, so as to have the weakest part of the mixture next the firing-port and the richest nextthe pistomand then compress ing and adding the regenerative increment of heat (existing only about the compressionchamber) chiefly during the last moments of compression prior to the explosion, all substantially as set forth. :0

In testimony whereof I affix my signature in presence of two witnesses.

ARTHUR ROLLASON.

XVitnesses:

URANHALL CHAPMAN, WALTER J. SKERTEN. 

